Serum Interliukine-18 Level In Lung Cancer Patients And Its Clinic Significance

ObjectiveCancer immunity is a hot spot in cancer research at present. Especially , cytokines and their roles in cancer immunity are paid much attention to. It has been proved that lots of cytokines such as IL -2, IL - 12 and IFN -r have important roles in cancer immunity. Therefore , il is very important in clinic to evaluate the level and roles of these cytokines in patients with cancer.IL - 18 is an immune regulating factor which was found recently. IL - 18 is a cytokine which resembles IL - 1 structurally and IL - 12 functionally but exerts its effect independently of both. It can kill or inhibit tumor by inducing immune cells to proliferate and enforcing their activity, making cytokines secret, enhancing tumor cell apoptosis by Fas - FasL, and inhibiting tumor vascularization. Many scholars have evaluated serum IL - 18 level in cancer patients, but few scholars have evaluated serum IL -18 level in lung cancer patients.The aim of this research is to evaluate serum IL - 18 level in lung cancer patients, so as to further evaluate the immune status in lung cancer patients.Method57 inpatients (41 males and 16 females) with lung cancer were collected as experiment group from February 2002 to June 2002 in the Department of Thoracic Surgery, First Affiliated Hospital of China Medical University. The age ranged from 28 to 76 (mean, 58). They were divided by its pathological type and staging. According to 1997 UICC staging criteria, 35 cases were classified as stage I and II , 22 cases stage M and IV. According to WHO classification standard in 1998, 5 cases were large cell carcinoma, 7 cases small cell carcinoma, 21 cases squamous cell carcinoma and 24 cases adenocacinoma. They were pathologic diagnosis with paraffin section by First Affiliated Hospital of China Medical University. In squamous cell carcinoma and adenocacinoma, 21 cases were high differentiation, and 24 cases middle and low differentiation. 15 cases (9 males and 6 females) of health volunteers were selected as control. The age ranged from 36 to 64 ( mean, 50 ). Peripheral blood samples were obtained and serum was extract from them. Enzyme - linked immunosorbent assay (ELISA) was used to detect serum IL -18 level. The standard curve was established according to the IL - 18 standard concentration and the absorbance. The concentration was obtained from the standard curve. The difference between lung cancer patients and health volunteers was compared with t test. The difference between each stage and grading of lung cancer patients and health volunteers was compared with analysis of variance ( ANOVA). The difference between each pathological type of lung cancer patients and health volunteers was compared with Kruskal - Wallis test and multiple comparison. SPSS9.0 software was used to deal with and analysis the statistical data.ResultSerum IL -18 level in lung cancer patients was significantly decreased than that of health control. Serum IL - 18 level in each stage of lung cancer patients was significantly decreased than that of health control, but there was no significant difference between I , II stage and III,IV stage. There was no significant difference in serum IL - 18 between each pathological type of lung cancer, but they were significantly decreased than that of health volunteers. There was no significant difference in serum IL - 18 between each grading of lung cancer ( squamous cell carcinoma and adenocacinoma) , but they were significantly decreased than that of health control.Conclusion1. There was significantly decreased in the serum IL - 18 level of lung cancer patient.2. The serum IL - 18 level did not relate to the stage of lung cancer.3. The serum IL -18 level did not relate to the pathological type or histological differentiation of lung cancer.